EPA ponders rust fungus release to combat invasive plant

The Environmental Protection Agency has announced that the Marlborough District Council has applied to introduce the rust fungus on behalf of a consortium of regional councils and the Department of Conservation.

The fungus – Uromyces pencanus – infects the leaves of the invasive, non-native Chilean needle grass and competes with them for nutrients, with debilitating effects. Its spores spread rapidly on the wind.

Chilean needle grass is found at some 300 sites in New Zealand, covering around 4,000 hectares. But research suggests up to 15 million hectares may be potentially at risk.

Chilean needle grass is common in Australia and has caused production losses of up to 25 per cent in infested pastures. It displaces other types of grass, but is less palatable and nutritious to stock.

The grass also reduces the sale value of stock. Its sharply pointed seeds bore into the skins of grazing animals, damaging the pelt and reducing carcass value. It can also cause distressing wounds, sometimes blinding lambs and injuring farm dogs, according the the Environmental Protection Authority (EPA).

EPA cites a year-long study in Argentina, which found the fungus did not spread to plants other than the target needle grass. "Other research suggests there is no direct threat to non-target plants in New Zealand, so no native or ornamental plants would be at risk," it advises.

EPA is now inviting public submissions on this application.

Submissions open on 29 January 2018 and close on 13 March 2018.

Read the consultation documents

Image credit: ECan